A 5G communications system may support different services, different deployment scenarios, and different spectrums. The foregoing service may be, for example, an enhanced mobile broadband (eMBB) service, a machine type communication (MTC) service, an ultra-reliable and low latency communications (URLLC) service, a multimedia broadcast multicast service (MBMS), or a positioning service. The foregoing deployment scenario may be, for example, an indoor hotspot scenario, a dense urban scenario, a suburban scenario, an urban macro coverage scenario, or a high-speed railway scenario. The foregoing spectrum may be, for example, any frequency range within 100 GHz.
A serving cell of a network device in the 5G communications system may support a plurality of sets of system parameters, so that the serving cell may use different system parameters (numerology) in the different services, the different deployment scenarios, and the different spectrums. Each set of system parameters may include a subframe length, a quantity of symbols included in a subframe, a cyclic prefix length, and the like.
However, how to determine a system parameter used by the serving cell is a technical problem that needs to be resolved urgently.